The present invention relates generally to telephone systems and, more particularly, to a method of call record correlation in a telecommunications system. Most particularly, the present invention relates to a method of compound call record creation based on the call record correlation.
In general, the following definitions are common in the telephone industry, but are included herein for completeness and clarity of explanation.
Access Traffic
A compensation mechanism governed by tariffs and/or contracts for message traffic carried by interexchange carriers (IXC) and exchanged between the IXCs and local exchange carriers (LECs), independent local exchange carrier (ILECs), and competitive local exchange carrier (CLECs). This type of traffic is generally carried over a type of telephone trunk called a Feature Group D trunk or FG-D trunk, and typically carries the highest per-minute charge. Under access traffic, IXCs pay the other carriers for each Minute of Use (MOU) of traffic destined to the IXC or originating from the IXC.
Address Complete Message (ACM)
The ACM is used to acknowledge receipt of an initial address message (IAM) and to indicate that the called party is being alerted (e.g. via ringing).
ACM Timestamp
The time at which the telephone being called began alerting the user (e.g. ringing).
Answer Message (ANM)
The ANM is used to indicate that the user called has answered, end-to-end connection is established, and a conversation takes place.
ANM Timestamp
The time the operator of the telephone being called answered the telephone.
Arbitrage
As used herein and as commonly used in the telephone industry, it is the mis-routing of inter-carrier telephone calls in such a way as to violate existing regulatory tariffs and/or established inter-carrier contracts. The purpose of such mis-routing is typically to take advantage of lower rates associated with the delivery of telephone traffic via routes other than those established and required by such tariffs and contracts and as such may be fraudulent. Arbitrage typically occurs via the following techniques: (1) IXC access traffic delivered via CLECs and (2) transit traffic delivered via non-transit trunks. However, there are many other ways in which arbitrage can occur.
Backward Interwork Parameter
An indicator as to whether Signaling System 7 (SS7) and non-SS7 inter-working was encountered ahead of this point in the call.
Call Detail Record (CDR)
A collection of messages including parameters associated with each call which provide detail regarding the call origin, destination, and other details. Such CDRs typically include, for example, time stamping, calling party number, called party number and many more fields.
Called Number
The telephone number dialed by the calling user.
Calling Number
The telephone number of the user making the call.
Carrier Identification Code (CIC)
Parameters contained within the SS7 IAM message which can be used to identify the requested IXC.
CIC Parameter
The number identifying the IXC selected by the LEC.
Charge Number
The telephone number to which the call is charged. Typically it is the telephone number of the calling telephone. Competitive Local Exchange Carriers (CLEC)
A LEC but specifically referring to one that competes with the incumbent LEC.
Destination Point Code (DPC)
The SS7 node, e.g. switching office or Signaling Transfer Point (STP), that the message is being sent to.
End Office (EO)
A switching office normally referred to as an EO to which telephones (from homes or businesses) are connected via wires called “loops”.
Feature Group D Trunk (FG-D Trunk)
A type of telephone trunk. See Access Traffic.
Forward Interwork Parameter
An indicator as to whether SS7 and non-SS7 inter-working was encountered prior to the point in the call where the parameter is observed.
Independent Local Exchange Carriers (ILEC)
Generally refers to a LEC which co-existed with a local exchange carrier owned by the Regional Bell Operating Companies (RBOCs).
Initial Address Message (IAM)
The IAM is used to indicate the desire to set up a call. A trunk is seized and “reserved” for use in the call.
IAM Timestamp
The time the trunk was seized for transmission of an SS7 message.
Interconnect Carrier
Any carrier that interconnects with the LEC.
Interexchange Carriers (IXC)
An IXC transports calls from one LEC to another, or possibly the same LEC, throughout the IXC's serving area. The IXC's serving area would typically span more than one local access transport area (LATA), and the IXC receives messages from and delivers messages to local exchange carriers (LECs, CLECs, and ILECs) and other IXCs. Calls that span LATAs typically must use an IXC.
IXC Trunk
A trunk that comes from an IXC to a LEC.
Jurisdiction Indicator Parameter
A parameter contained in SS7 messages which, if available, indicates the geographic origin of a call.
Link Monitoring System (LMS)
A system that can be used to collect CDRs by monitoring SS7 links.
Local Access Transport Area (LATA)
The geographic area, determined at divestiture, within which a LEC provides service is typically divided into various areas referred to as LATAs.
Local Exchange Carrier (LEC)
A LEC is a telephone service provider that provides telephone service to its customers in a specific geographical serving area. A LEC would typically be a local telephone company.
Local Exchange Routing Guide (LERG)
A document defining the specific LATA within which a given telephone number is located.
Location Routing Number (LRN)
A number obtained from the database at the service control point (SCP). The SCP converts the called number into the LRN which is the number used by the network to get the call to its final destination.
Loop
Telephones are connected (from homes or businesses) via wires called “loops” to a switching office normally referred to as an EO.
Meet-Point Billing
Traffic exchanged between IXCs and ILECs destined for LEC customers (in cases where the IXC does not directly interconnect with the LEC) is governed by tariffs and/or contracts, using a compensation mechanism referred to as meet-point billing. Under meet-point billing, IXCs pay the ILEC a fee, part of which is subsequently paid by the ILEC to the LEC for each MOU of traffic between the IXC and the LEC.
Minute of Use (MOU)
For billing purposes a measure of the time which a given carrier's resources are consumed providing a given service.
Numbering Plan Address (NPA)
More commonly known as the area code of the telephone number.
NPANXX
The NPA plus the next three digits of the telephone number.
Originating Point Code (OPC)
The SS7 node, e.g. switching office or STP, that is sending the message.
Reciprocal Compensation
Under reciprocal compensation, carriers pay each other a usage fee for each MOU of traffic delivered from their network to the other carrier's network. This message traffic is typically traffic exchanged between various LECs and their CLECs and ILECs. This type of traffic is generally carried over a type of telephone trunk called a local trunk.
Release Complete Message (RLC)
The RLC is sent when the second of the two connected parties hangs up. At that point the trunk is released.
RLC Timestamp
The time the operator of the second telephone to hang up did so.
Release Message (REL)
The REL indicates that the first of the two connected parties has hung up.
REL Timestamp
The time the operator of the first telephone to hang up did so.
Remote Site Processors
A device used to consolidate partial CDRs into complete CDR's.
Service Control Point (SCP)
A network database used to translate called numbers into local routing number which translates the called number in the location routing number (LRN).
Signaling Transfer Points (STPs)
At the heart of the SS7 network are packet switches known as STPs. STPs are deployed in pairs in the North American SS7 network to provide communication path redundancy. Different carriers own a portion of the SS7 network and interconnect their EOs and tandems to the overall SS7 network so as to enable end-to-end communication between carriers.
SS7 Links
The communication links over which SS7 traffic is carried.
SS7 Network
The SS7 messages are transported over a secure data network referred to as the “SS7 network”. The SS7 network comprises various SS7 Links along with STPs.
SS7 Protocol
To perform the task of call setup and tear down when multiple end offices EOs are involved, switching offices communicate with each other using a signaling protocol referred to as SS7, carried over SS7 links. SS7 messages are used in specific sequences to perform various tasks required to establish telephone connections. Telephone calls between two customers connected to the same EO will be handled by the application logic contained in the EO, and will not require the use of the SS7 protocol.
Tandem
In certain cases, for example two towns that are somewhat far apart, a type of switching center called a “tandem” is involved in establishing connectivity between two customers.
Trunk Circuit Identification Code (TCIC)
Between any two telephone switches there may a trunk group which comprises several trunks. These trunks are identified via the TCIC.
Transit Network Selection (TNS)
Parameters contained within the SS7 IAM message which can be used to identify the requested IXC.
Transit Traffic
Traffic that goes thru a LEC network but does not originate or terminate in that LEC and uses trunks other than those specifically designated for such traffic.
Trunk
When telephones are served from different EO's (e.g. in different towns), they are interconnected via wires called “trunks” between the EO's.
Unbundled Network Elements (UNE)
UNEs are a requirement mandated by the Telecommunications Act of 1996. They are the parts of the network that the ILECs are required to offer on an unbundled basis. Together, these parts make up a loop that connects to a Digital Subscriber Line Access Multiplexer (DSLAM) or a voice switch (or both). The loop allows non-facilities-based telecommunications providers to deliver service without laying network infrastructure (copper/fiber).
UNE-Platform (UNE-P)
UNE-P is a combination of UNEs (loop+port is SBC's definition, port involves switching which is bought per minute at a “cost” rate from the RBOCs) that allow end-to-end service delivery without ANY facilities. Despite not involving any CLEC facilities, it still requires facilities-based certification from the Public Utilities Commission (PUC) to deliver services via UNE-P.
Wide Area Network (WAN)
A communication network serving a large geographical area of interest.
In the telephone system, complex regulatory tariffs have been mandated and/or inter-carrier contracts have been negotiated between carriers which (a) regulate the way in which traffic is to be routed between them and (b) specify the rates at which various types of traffic are to be charged. It is often of financial advantage to mis-route calls in violation of these existing regulatory tariffs and/or established inter-carrier contracts. The common name for this manipulation is “arbitrage”. The intent of those perpetrating this mis-routing is to take advantage of lower rates associated with the delivery of telephone traffic via other than the proper routes. Confirming the presence of arbitrage and proper billing is often difficult due to the fact that call routing information is often missing or incomplete.
Previous methods for the determination of telephone traffic routing have been based upon a single call sample, e.g. a call record obtained at the point where the call originates or at the point where the call terminates. The information available within a single call record has limitations due to the fact that critical routing information may be (a) missing or (b) incorrect. These techniques have proven to be ineffective at determining the presence of arbitrage. Since in typical arbitrage situations, the local exchange carrier bills the interexchange carriers, there is a great financial incentive for the local exchange carrier to detect and stop arbitrage. Furthermore, since previous methods are both unreliable and labor intensive, there is a great need to improve manners for detecting arbitrage.
With respect to the overall problem of analyzing call routing, it is difficult to analyze call routing when call records are created for each individual call segment only. One possible solution is to produce multi-leg call records (referred to herein as consolidated call records (CCRs)) for calls that transit a monitored network. This is done by analyzing individual CDRs created by a network monitoring system where individual CDRs are created for each observed segment of the call. Disadvantages of this solution include: (a) CCRs are only created for calls that transit the monitored network and the solution only considers CDRs that are in regards to the transit part of the call path; and (b) the created CCR does not maintain the individual fields of the contributing CDRs, instead it includes information from the first and last relevant CDRs only. Another possible solution is a script that joins two CDRs into a single record for a single call. The disadvantage of this solution is that it only considers two CDRs.
A system and method are needed that identify arbitrage through a correlation process. Further, a system and method are needed that provide the aggregation of multiple CDRs, each pertaining to a given segment of the same call, into one compound call record while maintaining key parameters from each contributing CDR, the system and method relying on the correlation process of the present invention, or any other correlation process. Also, a system and method are needed to enrich the resulting compound CDR with analysis flags that compare parameters from one contributing CDR to another, providing analysts more information regarding the call.